John Sayers' Recording Studio Design Forum Archive

Hi folks,

I'm based in the UK, viewing houses at the minute and I have my eyes set on one with a large detached garage, which I'd hope to convert to a drum room. I have limited information so far but I'm hoping to get a little ahead of the game in terms of what I might be able to do with it.

I've been reading around general soundproofing concepts here and in other places but some direct input would be useful to make sure I'm not over-(or under-)doing it.

The room

As it stands the room is a large, brick built garage. It has "barn" style doors rather than the up-and-over style. From what I know so far:

- Brick-built
- Tiled roof (probably not much underneath it)
- Presumably concrete floor
- Narrow windows - around 1' high - running most of the length of the building. I can't tell you much about the material or framing yet, unfortunately.
- Barn doors (wood?)

If any more info would be useful I can try and get hold of it tomorrow when I view the house.

The usage

Playing the drums without upsetting the neighbours too much. Maybe recording the odd demo but honestly not too worried about noise getting in.

Here's the kicker - I'd be looking primarily to convert the room into a comfortable practice space that is fit for storing drums in (i.e. well-ventilated, not too hot or cold). What I'd like is for that room to have enough noise attenuation that I'm not going to upset the neighbours (in adjacent brick-built houses) and regret ever converting it, but I'm not necessarily concerned about studio-level isolation.

What I'd like to know is whether, for example, a simple garage conversion with a breeze block partition, an inner frame and couple of layers of drywall would likely be enough to achieve a "reasonable" level of noise reduction for my situation in lieu of more advanced decoupling techniques?

Apologies if the question is a little vague - what I'm trying to get a feel for is what would be the right balance to strike - how to ensure I don't convert the garage into something that's too invasively loud to use but also how to avoid embarking on an over-engineered soundproofing project (unless of course that's deemed necessary)...

Hi "antp", and Welcome!

What I'd like to know is whether, for example, a simple garage conversion with an inner frame and couple of layers of drywall would likely be enough to achieve a "reasonable" level of noise reduction for my situation in lieu of more advanced decoupling techniques?

Actually, what you describe IS the most advanced decoupling technique! The best isolation for the lowest cost is achieved by having a fully-decoupled 2-leaf MSM system, which is exactly what you described: The existing building shell is your "outer leaf", then you build a new stud frame just inside that and put sheathing on only ONE side of that. Assuming you do it correctly, that is indeed the best way to proceed. Highest isolation at lowest cost.

how to ensure I don't convert the garage into something that's too invasively loud to use but also how to avoid embarking on an over-engineered soundproofing project...

The only other alternative that you have, is to simply add more mass to the "shell" that you have at present. However, when you do the math, you'll see that trying to get good isolation from a single-leaf structure is going to cost you a lot more, and be less successful.... The laws of physics are against it.


- Stuart -

Soundman2020 wrote:Hi "antp", and Welcome!

...

- Stuart -

Hi - thanks for the welcome and very rapid feedback!

A few questions based on what you've said -

1. For the inner frame, would you typically fix the frame to the outer wall or just bolt it to the floor?
2. Most of the "room within a room" examples I've seen have used Isomax or some similar system to isolate the drywall from the frame - is that necessary in a scenario where you already have the two-leaf system in place? How much more effective would that be over, say, fixing the drywall directly to the studs?
3. Possibly a silly question, but, assuming I wanted to have a contractor complete this project for me, would the vague instruction of "please build me a partition wall and single-leaf timber frame with two layers of drywall inside it" typically be enough for your average building contractor to make a decent job of something like this?

1. For the inner frame, would you typically fix the frame to the outer wall or just bolt it to the floor?

ONLY to the floor. The inner-leaf frame must be entirely separate from the outer shell of the building: no mechanical contact at all, except for the floor.

2. Most of the "room within a room" examples I've seen have used Isomax or some similar system to isolate the drywall from the frame - is that necessary in a scenario where you already have the two-leaf system in place?

No, it is not necessary. In that scenario, it serves no useful purpose except to fill the pockets of your supplier with money! Clips+hat channel (or resilient channel by itself) are only needed in cases where it is not possible to build a separate decoupled-inner frame. In that case, they do work, and they do provide some decoupling of the drywall, but not nearly as much as what you can get by decoupling the framing itself. With clips, you are limited to around 10-15 dB of improvement in isolation, but with a decoupled frame you can easily get an improvement of 25 dB, or more.

How much more effective would that be over, say, fixing the drywall directly to the studs?

For the case of having no separate second frame, then clips do provide a good improvement. But for the case where you DO have a second, decoupled wall, there's no advantage. If the wall is decoupled, then it is decoupled! It makes no sense to decouple it again...

3. Possibly a silly question, but, assuming I wanted to have a contractor complete this project for me, would the vague instruction of "please build me a partition wall and single-leaf timber frame with two layers of drywall inside it" typically be enough for your average building contractor to make a decent job of something like this?

Nope! That's an excellent question, actually! The average contractor has no understanding of acoustic isolation concepts, nor the underlying principles. You would have to explain to him, very carefully, and in writing, exactly how to do this. If not, he'll probably nail the inner-leaf walls to the roof trusses as well as the floor (thus trashing your isolation), then proceed to leave gaps and cracks all around the place (thus trashing your isolation), put no seals on your doors or windows, use a hollow door, then get his electrician to cut holes in your drywall for the electrical boxes, and get his HVAC sub-contractor to cut more holes on your drywall for the ventilation registers.... like that, you'd get no isolation at all. All the effort and expense would be wasted. If you can find a contractor with prior proven experience in building studios, then that's wonderful! If not, you'll have to carefully train yours, then supervise like a hawk, watching everything he does, closely...

If you want to read a really sad story (with a happier ending!) about what can go wrong with contractors who think they know about acoustics but actually don't, then go grab yourself a coffee and a big bag of popcorn, and read this thread: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=17363 . It works out well in the end, but poor Beeros went through some pretty tough problems to get it fixed!

Forewarned is forearmed...




- Stuart -

That's awesome thanks - and I had already read through that thread, which is exactly the kind of thing I had imagined could happen...

I guess my worry is that as a layman I'm not sure I'd be confident in instructing and supervising a contractor on a job like this since I've no idea what traps to watch out for and I"d be concerned that even if I read up on how to properly manage ventilation and power, how to build a doorframe that won't just short-circuit the room... there are probably gotchas that I would have no hope of catching.

But then, without having that knowledge, how would you find and assess a consultant who does

Maybe it's time to get studying...

OK, so I'm viewing the house later and will try and get a better idea of the garage when I'm there - particularly around the dimensions, construction materials, windows, roof...

I'd also like to start reading around how to do ventilation and electrics properly but struggling to find a straightforward resource? From what I can find here it seems like the best bet is surface-mounted electrics with the initial cabling run through as small a hole in the drywall as possible and then acoustically sealed. What about ventilation?

If all goes well and we end up offering then I'll come back with proper dB readings in due course.

I'd also like to start reading around how to do ventilation and electrics properly but struggling to find a straightforward resource? From what I can find here it seems like the best bet is surface-mounted electrics with the initial cabling run through as small a hole in the drywall as possible and then acoustically sealed. What about ventilation?

As luck would have it, just this morning I wrote up an explanation about ventilation on another thread, earlier this morning. Not sure if it's everything you need, but it should put you on the right track to get a rough idea: http://www.johnlsayers.com/phpBB2/viewt ... 6&start=45 .

- Stuart -

Soundman2020 wrote:

I'd also like to start reading around how to do ventilation and electrics properly but struggling to find a straightforward resource? From what I can find here it seems like the best bet is surface-mounted electrics with the initial cabling run through as small a hole in the drywall as possible and then acoustically sealed. What about ventilation?

As luck would have it, just this morning I wrote up an explanation about ventilation on another thread, earlier this morning. Not sure if it's everything you need, but it should put you on the right track to get a rough idea: http://www.johnlsayers.com/phpBB2/viewt ... 6&start=45 .

- Stuart -

Lots of awesome info, thanks - I will get reading.

Unfortunately the house and the garage were both a little on the small side (8' wide and only 6' or so to the eaves in the case of the garage) so that plan might be out the window, but we are looking at some others that have basement space or garden space to potentially build a little outdoor studio. I think I'll probably lurk for a while and then come back once I have the beginnings of a real plan...